An article that a "Pawpaw enthusiast" might be interested in is:
Wilson, M.F. and D.W. Schemske. 1980. Pollinator limitation, fruit production,
and floral display in Pawpaw (asimina triloba). Bulletin of the Torrey
Botanical Club 107:401-408.
Department of Botany
University of Washington, Seattle
bishopj at botany.washington.edu